This invention relates to hydroconversion processes using a new class of aromatic-metal chelate compositions which are characterized as being hydrogen deficient and cross-linked and containing two or more heteroatoms wherein at least one of the heteroatoms is part of a 5 or 6 member heterocyclic ring. The hydroconversion processes include hydrogenation hydrotreating, hydrodesulfurization, hydrocracking, and reforming.
In the future, increasing amounts of the world's energy needs will be met by use of heavy liquid and solid hydrocarbonaceous materials. Although much of the world's energy needs will probably be met by burning these heavy hydrocarbonaceous materials in electric generating plants, a substantial portion of the world's energy needs will not able to be supplied in the form of centrally generated electricity. One such need will be for transportation fuels, such as, gasoline, jet fuel, and diesel fuels. At some point in the future, a portion of these transportation fuels will have to be prepared from heavy hydrocarbonaceous raw materials. Even unexpected discoveries of large new fields of conventional petroleum will only put off that point in the future by a number of years. As a result, much work is being done to develop economical methods for converting these heavy hydrocarbonaceous materials, which in most cases are highly contaminated, to light, clean, desirable products.
There are several approaches to the conversion of heavy hydrocarbonaceous materials to lighter products. One approach, and probably the oldest and most widely used, is simply pyrolysis, or coking. One drawback with coking is that a significant fraction of the feed is converted to gas and coke at the expense of potentially more valuable liquid products. While there is no problem in processing such heavy materials by coking, the yield of coke, in some cases, can amount to up to about 20 weight percent, or more. The coke is often of poor quality because of large amounts of heteroatom impurities.
Another approach is hydroconversion which offers the potential for substantially complete recovery of the heavy feed, including coke precursors, as valuable liquid products and/or good quality hydrocarbons for further upgrading. Despite strong liquid yield incentives, hydroconversion using conventional technology has not displaced coking because of the poor quality of these feeds and the consequent adverse effect on catalyst life expectancy. Compared to conventional light crude oils, these heavier materials are usually rich in high molecular weight, hydrogen lean, asphaltenic materials, which contain high concentrations of sulfur, nitrogen, and metal contaminants. Whereas coking simply rejects the worst of these objectionable materials in the coke phase, hydroconversion must cope with all of them to be successful. For example, rapid heterogeneous catalyst deactivation is a major problem owing to large asphaltenic molecules and deposition of the feed metal contaminants in the catalyst pores. Also, particulate matter contained in certain heavy feeds can lead to plugging of reactors.
Examples of conventional commercial processes for heavy feed upgrading include the so called H-Oil (Hydrocarbon Research Incorporated) and LC Fining (LUMMUS/Cities Service) processes. Both of these commercial processes suffer the limitation of catalyst deactivation by metal deposition.
Another commercial hydroconversion process which has met with limited success is the slurry process wherein the heavy feed is slurried using a finely divided catalyst, such as a vanadium sulfide catalyst.
One of the most promising hydroconversion technologies to be developed in recent years is the use of micron-size catalytic materials which comprise a metal sulfide component in a hydrocarbonaceous matrix. Such catalytic materials are generated in situ in the feeds at hydroconversion conditions from small amounts of certain oil soluble or oil dispersible metal compounds. See U.S. Pat. Nos. 4,134,825; 4,266,742; and 4,244,839 all to Exxon Research and Engineering Company.
Although all of the above discussed processes have met with varying degrees of commercial success, there is still a pressing need in the art for the development of more economical methods, and more effective catalysts, for upgrading heavy hydrocarbonaceous materials.